Omaha, NE (LifeNews.com) — Investment guru Warren Buffett says he will donate the bulk of his fortune to the pro-abortion foundation set up by Microsoft founder Bill Gates and his wife. That the world’s second richest man would leave about 80 percent of his estate to the Gates’ foundation is a huge concern for pro-life advocates because of the groups it supports.

Buffett is the 75 year-old chairman and CEO of Berkshire Hathaway and he told Fortune magazine he will begin making contributions to the Bill and Melinda Gates foundation next month by giving it stock options in the company.

According to an Associated Press report, Buffett will give the Gates foundation 12,050,000 in Class B shares of Berkshire Hathaway. One share of the stock sells for just over $3,000, and would give the Gates foundation another $37 billion. It already has $29 billion, which makes it the world’s largest charity.

The donation causes huge concerns for pro-life advocates as the Gates Foundation has given the Planned Parenthood Federation of America abortion business almost $12.5 million since 1998, including funds to persuade teenagers to support abortion and to lobby the United Nations to advance pro-abortion proposals.

The Gates foundation has also given nearly $21 million to the International Planned Parenthood abortion business over the last seven years. The funds have gone to promote abortions in third-world nations and to set up pro-abortion family planning centers in South America, Africa and eastern European nations.

Bill Gates and his wife have also spent millions promoting abortion closer to home.

Their foundation has given nearly $2 million to Planned Parenthood of Central Washington and Planned Parenthood of Western Washington to fund abortion centers. The Gates Foundation also gave the Planned Parenthood Federation of Canada more than $1.3 million to promote abortions there.

"The tragedy of Bill Gates’ support of abortion and population control is that technology leads to development," says Steven Mosher, President of the Population Research Institute.

"Unfortunately, the developing world will grow old before it develops because of population control. Gates, in supporting population control, is out of step with other great minds who have viewed people as humanity’s greatest resource," Mosher said.

Mosher’s group, at Microsoft’s 2003 annual shareholders meeting, failed to win approval for a motion to stop Microsoft from directly contributing to charities, citing its support for Planned Parenthood.

Buffett’s decision surprises some, as he was expected to leave his fortune to his wife’s foundation — the Susan Thompson Buffett foundation that she founded.

Buffett told Fortune it was easier to give his money to a large existing foundation rather than try to build his own.

"What can be more logical, in whatever you want done, than finding someone better equipped than you are to do it?” Buffett said. "Who wouldn’t select Tiger Woods to take his place in a high-stakes golf game? That’s how I feel about this decision about my money.”

Gates, who recently stepped down as the head of Microsoft to focus on the foundation, and Buffett are long-time friends and Gates serves as a board member of Berkshire Hathaway.